code: def transform(self, input_array: np.ndarray):
      res = input_array - np.mean(input_array)
      res = res / np.std(res)
      res = res * self.std
      res = res + self.mean
      return res
  
file_path: popmon/tests/popmon/base/test_module.py
imports: import numpy
  import pytest
  from popmon.base import Module
label_desc: Use image node_id 2 for calling the Scaler obj's underlying member method code with example usage: obj.transform(input_array) and returns: res